1. Field of the Invention
The present invention relates to a paper feeding cassette and an image forming apparatus.
2. Description of the Related Art
The image forming apparatus such as a copy machine, a printer, a facsimile machine, and a multifunctional complex machine employs an electrophotographic system for a process of forming an image onto a paper medium (a sheet of paper). In the electrophotographic system, a toner image which is a visible image is formed on the photoreceptor serving as a recording medium, and then transferred onto the paper medium such as plain paper. In order to keep the toner image held on this paper medium as a permanent image, for example, the paper medium is passed through a heat fixing apparatus to cause the toner to be fixed thereon. Then, the paper medium is discharged from the image forming apparatus to the outside.
The above-described image forming apparatus has a lower stage provided with a paper feeding cassette for storing paper media. In order to accommodate various sizes of paper media, this paper feeding cassette is provided with a side edge regulating plate for regulating the position of both side edges of the paper media and a trailing edge regulating plate for regulating the position of the trailing edge of the paper media in the direction in which the paper media are fed. Japanese Laid-Open Patent Publication No. 2000-016601 is cited as a prior art document disclosing that a paper feeding cassette is provided with a trailing edge regulating plate.
It is effective to provide a trailing edge regulating plate in the paper feeding cassette so as to accommodate various sizes of paper media. However, the paper feeding cassette is required to have a space for providing a trailing edge regulating plate. This may cause an increase in the size of the paper feeding cassette, which also leads to an increase in the area of the floor of the image forming apparatus.
In addition, the trailing edge regulating plate is required to reliably regulate the position of not only a sheet of paper but also stacked sheets of paper.
Accordingly, in order to sufficiently ensure the space for providing a trailing edge regulating plate without changing the area size of the floor of the image forming apparatus, it is necessary to reduce the capacity and decrease the maximum size of the paper media that can be stored in the paper feeding cassette.